25 research outputs found
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Pilot test of a vacuum extraction system for environmental remediation of chlorinated solvents at the Savannah River Site
Vacuum extraction is an environmental restoration technique that is currently being applied to the remediation of soils and shallow segments that are contaminated with volatile constituents. In 1987, a h study was performed to evaluate the performance and potential applicability of this technology at the Savannah River Site (SRS). Vacuum extraction is useful when volatile constituents are present in the vadose zone. The technology has been used to remediate a number of sites across the country, including leading underground storage tanks, spill sites, landfill, and production facilities. The primary objective of the pilot study was to test the performance of the technology under the conditions specific to many of the potential areas of application at SRS. There is only a limited body of literature documenting field studiesin similar environments with in sands and clayey zones and a relatively thick vadose zone. Careful studies of this type are needed to develop full scale designs at SRS. The vacuum extraction pilot study at SRS was performed by a mm consisting of technical representatives of the Environmental Sciences Section in the Savannah River Laboratory (SRL), the Raw Materials Engineering and Technology Section of SRS, and TerraVac Inc., a subcontractor with experience in this field
Development and validation of a predictive model for death in acquired severe ADAMTS13 deficiency-associated idiopathic thrombotic thrombocytopenic purpura: the French TMA Reference Center experience
Splenectomy and/or cyclophosphamide as salvage therapies in thrombotic thrombocytopenic purpura: the French TMA Reference Center experience: SALVAGE THERAPIES IN SEVERE TTP
BACKGROUND: The objective was to assess the efficacy and safety of splenectomy and cyclophosphamide as salvage therapies in severe thrombotic thrombocytopenic purpura (TTP).STUDY DESIGN AND METHODS: During a 10-year period, patients who did not improve with plasma exchanges, steroids, vincristine, and/or rituximab were considered for splenectomy or cyclophosphamide. Patients with a documented severe (<10% of normal value) acquired ADAMTS13 deficiency are reported here. RESULTS: Eighteen patients with a severe acquired ADAMTS13 deficiency required a salvage therapy. Thirteen patients had a splenectomy 19 (interquartile range [IQR], 10-51) days after TTP diagnosis. One patient died the day after splenectomy. The remaining patients improved platelets (PLTs) until Day 6, along with a rapid and major lactate dehydrogenase improvement. Six patients, however, subsequently experienced a transient worsening. Durable PLT count recovery in survivors was observed within 13 (IQR, 11.5-25.5) days. Postoperative complications included thromboembolic events (two cases) and infections (five cases). Five patients received pulses of cyclophosphamide 12 (IQR, 12-15) days after TTP diagnosis. All patients recovered PLTs 10 (IQR, 9-24) days after the first pulse and two experienced a transient worsening. Three patients experienced infections. Three relapses occurred 5 months, 2.5 years, and 4.5 years after splenectomy and one relapse occurred 3.5 years after cyclophosphamide. After a 2.5 (IQR, 0.75-6.2)-year follow-up, the overall survival was 94%. CONCLUSION: Cyclophosphamide and splenectomy provide comparable high remission rates in severe TTP with acceptable side effects and should be considered in the more severe patients who do not improve with other therapies
Accuracy Assessment of the ESA CCI 20M Land Cover Map: Kenya, Gabon, Ivory Coast and South Africa
This working paper presents the overall and spatial accuracy assessment of the European Space Agency (ESA) 20 m prototype land cover map for Africa for four countries: Kenya, Gabon, Ivory Coast and South Africa. This accuracy assessment was undertaken as part of the ESA-funded CrowdVal project. The results varied from 44% (for South Africa) to 91% (for Gabon). In the case of Kenya (56% overall accuracy) and South Africa, these values are largely caused by the confusion between grassland and shrubland. However, if a weighted confusion matrix is used, which diminishes the importance of the confusion between grassland and shrubs, the overall accuracy for Kenya increases to 79% and for South Africa, 75%. The overall accuracy for Ivory Coast (47%) is a result of a highly fragmented land cover, which makes it a difficult country to map with remote sensing. The exception was Gabon with a high overall accuracy of 91%, but this can be explained by the high amount of tree cover across the country, which is a relatively easy class to map
Prévision de l'éruption dentaire
AprÚs une évocation rapide du phénomÚne mal connu de l'éruption dentaire, les problÚmes posés par l'ùge dentaire et la prévision de l'apparition clinique des dents seront abordés.
A la lumiĂšre des travaux de l'Ăcole AmĂ©ricaine de Moorrees, il apparaĂźt qu'une rĂ©ponse satisfaisante sur le plan clinique ne peut ĂȘtre donnĂ©e sans que l'orthodontiste dispose d'Ă©lĂ©ments tels que :
â la dĂ©termination du stade de formation radiculaire, qui semble ĂȘtre un indice de maturation prĂ©cis ;
â l'Ă©valuation du temps de calcification qui sĂ©pare les diffĂ©rents stades de leur formation ;
â la connaissance des facteurs gĂ©nĂ©raux et surtout locaux susceptibles de retarder ou d'accĂ©lĂ©rer l'Ă©ruption dentaire
VSURF : un package R pour la sĂ©lection de variables Ă l'aide de forĂȘts alĂ©atoires
National audienceVariable selection is a crucial issue in many applied classication and regression problems. It is of interest for statistical analysis as well as for modelization or prediction purposes to remove irrelevant variables, to select all important ones or to determine a sucient subset for prediction. These main different objectives on a statistical learning perspective involve variable selection to simplify statistical problems, to help diagnosis and interpretation, and to speed up data processing. The authors have proposed a variable selection method based on random forests, and the aim of this presentation is to describe the (recently available on CRAN) associated R package called VSURF and to illustrate its use on real datasets. Introduced by Breiman, random forests (abbreviated RF in the sequel) is an attractive non-parametric statistical method to deal with such problems, since it requires only mild conditions on the model supposed to have generated the observed data. Indeed, since it is based on decision trees and it uses aggregation ideas, RF allow to consider in an elegant and versatile framework dierent models and problems, namely regressions, two-class or multiclass classications. In Genuer et.al. 2010 we have distinguished two variable selection objectives: interpretation and prediction. The first is to find important variables highly related to the response variable in order to select all the important variables, even with high redundancy. The second is to find a small number of variables sucient to a good parsimonious prediction of the response variable. We have proposed the following two-step procedure, the first one is the same for the two situations while the second one depends on the objective
Long-term clinical and urodynamic effectiveness of augmentation ileocystoplasty with supra-trigonal cystectomy in individuals with spinal cord injury
International audiencePurpose: This study aimed to determine the long-term effectiveness of augmentation ileocystoplasty (AI) associated with supra-trigonal cystectomy on clinical and urodynamic variables, and the safety of the intervention in individuals with spinal cord injury (SCI). Materials and methods: Single-center, retrospective study of all patients with SCI who underwent AI with supra-trigonal cystectomy from January 1994, with a follow-up of more than 8Â years. The primary outcome was the sustained long-term effectiveness of AI with supra-trigonal cystectomy on clinical and urodynamic variables. The secondary outcome was the long-term safety of this procedure. Results: We included 77 patients: 57% were female, mean (SD) age was 52.0 (13.0) years, 77% had paraplegia, and median time since onset was 25.0 [19; 30] years. Long-term success rate (evaluated 13 [10; 15] years post AI) was 93.5% for urodynamic parameters and 76.6% for urinary incontinence. Results of the short- and long-term post-AI assessments did not differ for any urodynamic or clinical variables. Bladder lithiasis occurred in 20.5% of cases and â„ 1 febrile urinary tract infection occurred in 55.8%, mostly within the first 2Â years of follow-up. No cases of bladder cancer were diagnosed. Conclusion: AI associated with supra-trigonal cystectomy in patients with SCI is safe and effective in both the short term and long term. Regular urodynamic assessment is not necessary in clinically stable patients with low bladder risk; however, close monitoring is important because of the risk of urological complications